Program testf
c     This program fills and then accesses an array of 16M real 
c     values (64 Mbyte).  While filling the array it writes out
c     every 16th element to a file (final size 4 Mbyte).
c     The program is intended to force paging and I/O, and
c     not compare vectorised/non-vectorised performance,
c     safe optimisation but no automatic vectorisation
c     may be used.
      parameter (n=10,m=1600000)
      real a(m*n)
      integer ihist(n)
      open(unit=1,file='testf.out',form='unformatted')
      do 10,i=1,n
         do 20,j=1,m
            a(i*j)=sin(mod(real(j),3.141593))
   20    continue
         ihist(i)=0
         write(unit=1)(a(i*k),k=16,m,16)
   10 continue
c
      do 30,i=1,m*n
         j=9.99*a(i)+1
         ihist(j)=ihist(j)+1
   30 continue
c
      do 40,i=1,n
         print*,i,ihist(i)
   40 continue
c
      close(unit=1)
      stop
      end